We lease a portion of our rental equipment and certain of our facilities under operating leases with terms that expire at various dates substantially through 2024. As of March 31, 2018, we have guaranteed $15.7 million of residual values for these rental equipment assets at the end of the respective lease terms. Certain leases contain renewal and fair market value purchase options as well as mileage and other restrictions. At the expiration of the lease, we have the option to renew the lease, purchase the asset for fair market value, or sell the asset to a third party on behalf of the lessor. We have been leasing equipment since 1987 and have experienced no material losses relating to these types of residual value guarantees.

		Years Ended March 31,
		2018		2017		2016
		(In thousands)
Lease expense	$	33,960	$	37,343	$	49,780

Operating and ground lease commitments for leases having terms of more than one year were as follows:

		Property, Plant and Equipment				Rental Equipment
		Ground		Operating		Operating		Total
		(In thousands)
Year-ended March 31:
2019	$	991	$	17,014	$	9,010	$	27,015
2020		1,024		17,217		1,300		19,541
2021		1,024		16,699		–		17,723
2022		1,030		15,066		–		16,096
2023		1,030		14,693		–		15,723
Thereafter		49,649		20,163		–		69,812
Total	$	54,748	$	100,852	$	10,310	$	165,910